The Role of the N-Domain in the ATPase Activity of the Mammalian AAA ATPase p97/VCP*
| Autor: | Heidi O. Yeung, Chun Tsang, Hajime Niwa, Caroline A. Ewens, Paul S. Freemont, Xiaodong Zhang |
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| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
Models
Molecular Protein Conformation ATPase Valosin-containing protein Protein domain ATPases Protein Turnover Mutation Missense Enzyme Mechanisms Cell Cycle Proteins Protomer Random hexamer Biochemistry 03 medical and health sciences Structure-Activity Relationship 0302 clinical medicine Adenosine Triphosphate Protein Domains ATP hydrolysis Valosin Containing Protein Humans Molecular Biology 030304 developmental biology Adenosine Triphosphatases 0303 health sciences biology Hydrolysis Wild type Molecular Bases of Disease Cell Biology Osteitis Deformans AAA proteins Protein Structure Tertiary Amino Acid Substitution p97/VCP Mutagenesis Frontotemporal Dementia biology.protein 030217 neurology & neurosurgery |
| Zdroj: | The Journal of Biological Chemistry |
| ISSN: | 1083-351X 0021-9258 |
| Popis: | Background: p97/VCP disease-linked mutations increase ATPase activity and destabilize the N-D1 domain interaction. Results: Increased N-domain flexibility in p97/VCP increases ATPase activity, whereas locking down the N-domain decreases it. Conclusion: The p97/VCP N-domain position relative to the D1 ring is linked to ATP hydrolysis ability. Significance: p97/VCP N-domain conformational changes cause transitions between an active and inactive state. p97/valosin-containing protein (VCP) is a type II ATPase associated with various cellular activities that forms a homohexamer with each protomer containing an N-terminal domain (N-domain); two ATPase domains, D1 and D2; and a disordered C-terminal region. Little is known about the role of the N-domain or the C-terminal region in the p97 ATPase cycle. In the p97-associated human disease inclusion body myopathy associated with Paget disease of bone and frontotemporal dementia, the majority of missense mutations are located at the N-domain D1 interface. Structure-based predictions suggest that such mutations affect the interaction of the N-domain with D1. Here we have tested ten major inclusion body myopathy associated with Paget disease of bone and frontotemporal dementia-linked mutants for ATPase activity and found that all have increased activity over the wild type, with one mutant, p97A232E, having three times higher activity. Further mutagenesis of p97A232E shows that the increase in ATPase activity is mediated through D2 and requires both the N-domain and a flexible ND1 linker. A disulfide mutation that locks the N-domain to D1 in a coplanar position reversibly abrogates ATPase activity. A cryo-EM reconstruction of p97A232E suggests that the N-domains are flexible. Removal of the C-terminal region also reduces ATPase activity. Taken together, our data suggest that the conformation of the N-domain in relation to the D1-D2 hexamer is directly linked to ATP hydrolysis and that the C-terminal region is required for hexamer stability. This leads us to propose a model where the N-domain adopts either of two conformations: a flexible conformation compatible with ATP hydrolysis or a coplanar conformation that is inactive. |
| Databáze: | OpenAIRE |
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